This invention relates generally to separation of gas and liquid in a flow of a mixture of the gas and liquid; more particularly it concerns enhancing separation efficiency through provision for seeding of the flow.
Many processes in the production of natural gas and industrial gases require the dehydration of the gas and/or the lowering of the temperature (dewpoint) at which liquids form from a saturated gas. This is accomplished by an expansion to lower temperature followed by separation of the liquids that have formed.
In a turbo compressor, the separated gas is transferred from the external separator to a compressor, driven by the shaft of the turbo expander. The gas is then compressed for transfer in a pipeline, for example. The droplets formed during the expansion of a saturated gas are formed by spontaneous condensation as the temperature is lowered. The diameters of droplets thus formed is very small, typically less than one ten millionth of a meter (less than one tenth of a micron). As a result, the separator in conventional dehydration or dewpointing installation must be very large. Separation using centrifugal or compact cyclonic separators is also difficult because of the small size. There is need for method and apparatus producing efficient separators in smaller installations.